A variety of new organophosphorus compounds are to be prepared for anticancer screening. Emphasis will be placed on derivatives of the cyclohexano (b) phosphole system, where the rings can be in various stages of saturation. At phosphorus, substituents may be hydrogen, alkyl, or halide. Of special interest will be the synthesis of P-halo derivatives, which will be useful as intermediates for other structures. Derivatives of ring systems containing P or N heterocyclic atoms in the cyclohexano moiety will also be sought.